Conditions trapping of fluids within an organ can create pressure within the organ leading to organ damage. For example, hydrocephalus, or “water on the brain,” resulting from an over-accumulation of cerebrospinal fluid (“CSF”), can increase intracranial pressure to the extent of causing mental disability or even death. There are some 69,000 hospital admissions for this condition annually in the United States alone, followed by some 39,000 shunting procedures to shunt CSF from brain ventricles to relieve overpressure. Berlis et al., Operative Neurosurgery 59:474-480 (2006), reported the drainage of an intracranial cyst by use of a balloon-mounted vascular stent.
It would be desirable to have additional means of relieving overpressure in hydrocephalus, and other conditions in which a fluid excess in a body cavity creates an overpressure on an organ.